drivers/gpu/drm/ttm/ttm_execbuf_util.c

   1 /**************************************************************************
   2  *
   3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include <drm/ttm/ttm_execbuf_util.h>
  29 #include <drm/ttm/ttm_bo_driver.h>
  30 #include <drm/ttm/ttm_placement.h>
  31 #include <linux/wait.h>
  32 #include <linux/sched.h>
  33 #include <linux/module.h>
  34
  35 static void ttm_eu_backoff_reservation_reverse(struct list_head *list,
  36                                               struct ttm_validate_buffer *entry)
  37 {
  38         list_for_each_entry_continue_reverse(entry, list, head) {
  39                 struct ttm_buffer_object *bo = entry->bo;
  40
  41                 __ttm_bo_unreserve(bo);
  42         }
  43 }
  44
  45 static void ttm_eu_del_from_lru_locked(struct list_head *list)
  46 {
  47         struct ttm_validate_buffer *entry;
  48
  49         list_for_each_entry(entry, list, head) {
  50                 struct ttm_buffer_object *bo = entry->bo;
  51                 unsigned put_count = ttm_bo_del_from_lru(bo);
  52
  53                 ttm_bo_list_ref_sub(bo, put_count, true);
  54         }
  55 }
  56
  57 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
  58                                 struct list_head *list)
  59 {
  60         struct ttm_validate_buffer *entry;
  61         struct ttm_bo_global *glob;
  62
  63         if (list_empty(list))
  64                 return;
  65
  66         entry = list_first_entry(list, struct ttm_validate_buffer, head);
  67         glob = entry->bo->glob;
  68
  69         spin_lock(&glob->lru_lock);
  70         list_for_each_entry(entry, list, head) {
  71                 struct ttm_buffer_object *bo = entry->bo;
  72
  73                 ttm_bo_add_to_lru(bo);
  74                 __ttm_bo_unreserve(bo);
  75         }
  76         spin_unlock(&glob->lru_lock);
  77
  78         if (ticket)
  79                 ww_acquire_fini(ticket);
  80 }
  81 EXPORT_SYMBOL(ttm_eu_backoff_reservation);
  82
  83 /*
  84  * Reserve buffers for validation.
  85  *
  86  * If a buffer in the list is marked for CPU access, we back off and
  87  * wait for that buffer to become free for GPU access.
  88  *
  89  * If a buffer is reserved for another validation, the validator with
  90  * the highest validation sequence backs off and waits for that buffer
  91  * to become unreserved. This prevents deadlocks when validating multiple
  92  * buffers in different orders.
  93  */
  94
  95 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
  96                            struct list_head *list, bool intr,
  97                            struct list_head *dups)
  98 {
  99         struct ttm_bo_global *glob;
 100         struct ttm_validate_buffer *entry;
 101         int ret;
 102
 103         if (list_empty(list))
 104                 return 0;
 105
 106         entry = list_first_entry(list, struct ttm_validate_buffer, head);
 107         glob = entry->bo->glob;
 108
 109         if (ticket)
 110                 ww_acquire_init(ticket, &reservation_ww_class);
 111
 112         list_for_each_entry(entry, list, head) {
 113                 struct ttm_buffer_object *bo = entry->bo;
 114
 115                 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), true,
 116                                        ticket);
 117                 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 118                         __ttm_bo_unreserve(bo);
 119
 120                         ret = -EBUSY;
 121
 122                 } else if (ret == -EALREADY && dups) {
 123                         struct ttm_validate_buffer *safe = entry;
 124                         entry = list_prev_entry(entry, head);
 125                         list_del(&safe->head);
 126                         list_add(&safe->head, dups);
 127                         continue;
 128                 }
 129
 130                 if (!ret) {
 131                         if (!entry->shared)
 132                                 continue;
 133
 134                         ret = reservation_object_reserve_shared(bo->resv);
 135                         if (!ret)
 136                                 continue;
 137                 }
 138
 139                 /* uh oh, we lost out, drop every reservation and try
 140                  * to only reserve this buffer, then start over if
 141                  * this succeeds.
 142                  */
 143                 ttm_eu_backoff_reservation_reverse(list, entry);
 144
 145                 if (ret == -EDEADLK && intr) {
 146                         ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
 147                                                                ticket);
 148                 } else if (ret == -EDEADLK) {
 149                         ww_mutex_lock_slow(&bo->resv->lock, ticket);
 150                         ret = 0;
 151                 }
 152
 153                 if (!ret && entry->shared)
 154                         ret = reservation_object_reserve_shared(bo->resv);
 155
 156                 if (unlikely(ret != 0)) {
 157                         if (ret == -EINTR)
 158                                 ret = -ERESTARTSYS;
 159                         if (ticket) {
 160                                 ww_acquire_done(ticket);
 161                                 ww_acquire_fini(ticket);
 162                         }
 163                         return ret;
 164                 }
 165
 166                 /* move this item to the front of the list,
 167                  * forces correct iteration of the loop without keeping track
 168                  */
 169                 list_del(&entry->head);
 170                 list_add(&entry->head, list);
 171         }
 172
 173         if (ticket)
 174                 ww_acquire_done(ticket);
 175         spin_lock(&glob->lru_lock);
 176         ttm_eu_del_from_lru_locked(list);
 177         spin_unlock(&glob->lru_lock);
 178         return 0;
 179 }
 180 EXPORT_SYMBOL(ttm_eu_reserve_buffers);
 181
 182 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
 183                                  struct list_head *list, struct fence *fence)
 184 {
 185         struct ttm_validate_buffer *entry;
 186         struct ttm_buffer_object *bo;
 187         struct ttm_bo_global *glob;
 188         struct ttm_bo_device *bdev;
 189         struct ttm_bo_driver *driver;
 190
 191         if (list_empty(list))
 192                 return;
 193
 194         bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
 195         bdev = bo->bdev;
 196         driver = bdev->driver;
 197         glob = bo->glob;
 198
 199         spin_lock(&glob->lru_lock);
 200
 201         list_for_each_entry(entry, list, head) {
 202                 bo = entry->bo;
 203                 if (entry->shared)
 204                         reservation_object_add_shared_fence(bo->resv, fence);
 205                 else
 206                         reservation_object_add_excl_fence(bo->resv, fence);
 207                 ttm_bo_add_to_lru(bo);
 208                 __ttm_bo_unreserve(bo);
 209         }
 210         spin_unlock(&glob->lru_lock);
 211         if (ticket)
 212                 ww_acquire_fini(ticket);
 213 }
 214 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);